/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.db.engine.querycontext;

import org.apache.iotdb.db.engine.storagegroup.TsFileResource;
import org.apache.iotdb.db.utils.DateTimeUtils;
import org.apache.iotdb.tsfile.read.filter.TimeFilter;
import org.apache.iotdb.tsfile.read.filter.basic.Filter;
import org.apache.iotdb.tsfile.read.filter.operator.AndFilter;

import java.util.List;

/**
 * The QueryDataSource contains all the seq and unseq TsFileResources for one timeseries in one
 * query
 */
public class QueryDataSource {

    /**
     * TsFileResources used by query job.
     *
     * <p>Note: Sequences under the same data region share two lists of TsFileResources (seq and
     * unseq).
     */
    private List<TsFileResource> seqResources;

    private List<TsFileResource> unseqResources;

    /* The traversal order of unseqResources (different for each device) */
    private int[] unSeqFileOrderIndex;

    /**
     * data older than currentTime - dataTTL should be ignored.
     */
    private long dataTTL = Long.MAX_VALUE;

    public QueryDataSource(List<TsFileResource> seqResources, List<TsFileResource> unseqResources) {
        this.seqResources = seqResources;
        this.unseqResources = unseqResources;
    }

    public List<TsFileResource> getSeqResources() {
        return seqResources;
    }

    public List<TsFileResource> getUnseqResources() {
        return unseqResources;
    }

    public void setUnSeqFileOrderIndex(int[] index) {
        this.unSeqFileOrderIndex = index;
    }

    public long getDataTTL() {
        return dataTTL;
    }

    public void setDataTTL(long dataTTL) {
        this.dataTTL = dataTTL;
    }

    /**
     * @return an updated filter concerning TTL
     */
    public Filter updateFilterUsingTTL(Filter filter) {
        return updateFilterUsingTTL(filter, dataTTL);
    }

    /**
     * @return an updated filter concerning TTL
     */
    public static Filter updateFilterUsingTTL(Filter filter, long dataTTL) {
        if (dataTTL != Long.MAX_VALUE) {
            if (filter != null) {
                filter = new AndFilter(filter, TimeFilter.gtEq(DateTimeUtils.currentTime() - dataTTL));
            } else {
                filter = TimeFilter.gtEq(DateTimeUtils.currentTime() - dataTTL);
            }
        }
        return filter;
    }

    public TsFileResource getSeqResourceByIndex(int curIndex) {
        if (curIndex < seqResources.size()) {
            return seqResources.get(curIndex);
        }
        return null;
    }

    public TsFileResource getUnseqResourceByIndex(int curIndex) {
        int actualIndex = unSeqFileOrderIndex[curIndex];
        if (actualIndex < unseqResources.size()) {
            return unseqResources.get(actualIndex);
        }
        return null;
    }

    public boolean hasNextSeqResource(int curIndex, boolean ascending) {
        return ascending ? curIndex < seqResources.size() : curIndex >= 0;
    }

    public boolean hasNextUnseqResource(int curIndex) {
        return curIndex < unseqResources.size();
    }

    public int getSeqResourcesSize() {
        return seqResources.size();
    }

    public int getUnseqResourcesSize() {
        return unseqResources.size();
    }
}
